Tibial cement mantle thickness is not affected by tourniquetless total knee arthroplasty when performed with tranexamic acid

Purpose Evidence exists that tourniquet use leads to increased cement penetration in total knee arthroplasty (TKA) due to decreased blood and fat in the bone during cementation. The use of tranexamic acid (TXA) has led to decreased blood loss and transfusion rates. The purpose of this study was to determine if the use of a tourniquet while utilising modern TXA protocols affects the tibial cement mantle penetration. Methods 140 patients who underwent primary TKA with and without a tourniquet (70 in each group) were retrospectively reviewed. All patients received a standard TXA protocol. The primary outcome measure was cumulative depth of cement mantle penetration of the tibial plateau on post-operative radiographs. Secondary outcome measures included post-operative change in haemoglobin and hematocrit levels, blood loss, and transfusion rates. Results There was no significant difference in age, sex, or pre-operative haemoglobin or hematocrit levels between groups. Tourniquet use resulted in significantly lower blood loss (100.0 mL versus 154.7 mL, p < 0.001), and significantly reduced drop in haemoglobin (1.8 g/dL vs 2.5 g/dL, p < 0.001) and hematocrit (5.7% vs 7.4%, p = 0.04) levels. However, depth of tibial cement mantle penetration did not differ between the tourniquet group (15.3 mm) and non-tourniquet group (15.0 mm, p value n.s.). No patient in either group required a blood transfusion. Conclusions Tourniquet use in primary TKA results in decreased blood loss and less change in pre-operative vs post-operative haemoglobin and hematocrit levels. However, with the use of TXA, not using a tourniquet resulted in similar cement mantle penetration around the tibial component as with a tourniquet.